With the advent of LED lamps (LED being the abbreviation for light-emitting diode), efficient, safe and long-lived lighting means are available. Similar to other light sources the brightness of LEDs can be adjusted by dimming. For this purpose different technologies for dimming a lamp have been developed, including analog or linear dimming and PWM dimming (PWM being the abbreviation for pulse-width-modulation). Compared to methods of linear dimming, PWM dimming has advantages such as high efficiency and accuracy as well as no CCT shift (CCT being the abbreviation for correlated color temperature).
However, PWM dimming may cause audible noise originating from the inductor and capacitor of the LED lamp driver operated at the PWM frequency. The inductor and capacitor of the LED lamp driver resonate at the PWM frequency which, in turn, may cause vibrations of other components such as a printed circuit board of the LED lamp driver.
In order to reduce noise during PWM dimming, the LED lamp driver may be insulated against sound and/or vibration (potting). Alternatively, components of low noise may be used. However, these solutions incur additional costs and space in order to be effective.